There has been a finding that patients with intractable hypertension who find it difficult to improve their high blood pressure even by taking antihypertensive can expect their blood pressure to be lowered by severing or disrupting the sympathetic nerve around the renal artery to block neurotransmission.
It has been proposed in the art to percutaneously sever the sympathetic nerve around the renal artery using an ablation catheter. For example, Japanese Laid-Open Patent Publication No. 2008-515544 (PCT) discloses an ablation catheter for severing the sympathetic nerve around the renal artery, the ablation catheter including a helical electrode disposed around an inflatable balloon for contacting and energizing the inner wall of a blood vessel. Similarly, Japanese Laid-Open Patent Publication No. 2010-509032 (PCT) discloses an electrode disposed around a positioning member such as a balloon or the like, the electrode being expandable into contact with the inner wall of a blood vessel for energizing.